This is an addon based on armor and weapon modifications:

Player suit with shirt, trousers, shoes and the equipment is the knife that if you watched the last episode of the series, each player has been granted.
Guardian suit with helmet, shirt, trousers, shoes and two types of guns. The helmet includes 3 types corresponding to three different guardian ranks with square, triangle and circle. When wearing the suit, you will gain health boost and strength effects. Equip with the outfit is a 20-shot pistol with 500 damage and a 30-shot rifle with 50 damage.
The boss suit with helmet, shirt, trousers, shoes and a 7-shot pistol with 1000 damage. You will gain fire resistance, health boost, instant health, night vision, regeneration, resistance, snow falling, strength and water breathing effects.
VIP guest suit has two different outfits, one black and one red for you to choose from, with all 4 main parts like The boss suit. The effect you get is the same as that of The boss suit.
The waiter who served VIP guest also had all of the above main part in his costume. The effects for this suit are health boost, instant health, night vision, resistance, snow falling and strength.
Finally, the robot doll with head, shirt, skirt and shoes has fire resistance, health boost, instant health, night vision, regeneration, resistance, strength and especially slowness. You can't move while wearing this suit. You can only turn your head and swing your arms.

(Note: You must wear the full suit to get the effect. The effect is mainly focused on the helmet, but you should wear full suit for it to work more effectively and avoid errors.)

You can get these items in the items menu, or type command: /give @s pa:<item name>.

Here is some picture:

INSTALLATION GUIDES: Download .mcaddon file and open it directly with Minecraft. You should enable all experimental modes in game options when create new world.

Squid Game Cosplay